a lot of = lots of,意思为许多的,很多,大量,后可接可数名词复数或不可数名词,后者是前者的缩略写法
没有lot of 一说
a lot是口语中的一个常用词组,多用于肯定句,有时也用于疑问句.其主要用法有如下几点：
一、作名词短语,表示“很多；多量”,在句中作主语、宾语或表语,其后常有动词不定式短语作后置定语,
如：
Sometimes we have very little snow,but sometimes there’s a lot.有时我们这儿雪很少,有时却又很多.（作主语）
He’s given her a lot to eat.他给了她许多好吃的东西.（作宾语）
This is a lot.这真多.（作表语）
二、作副词短语,在句中作程度状语,表示“很；非常；常常”,修饰动词、感叹词、介词短语、形容词或
副词的比较级,如：
It usually rains a lot/much at this time of year.每年这个时候都经常下雨.（修饰动词rain）
Do you wear your new watch a lot?你常戴你的新手表吗?（修饰动词wear）
Thanks a lot/very much ---that’s very kind.多谢,十分感激.（修饰感叹词thanks,thanks=thank you）
He is feeling a lot/much better.他感觉好多了.（修饰比较级better）
三、a lot前可被such,what,quite,rather修饰,如：
I like him quite a lot.我非常喜欢他.
---How much money is left?---还剩下多少钱?
---Rather a lot.---还有相当多.
四、a lot of = lots of,可修饰可数或不可数名词,意为“许多”,“大量的”,相当于many或much.a lot,a lot of,lots of通常用于肯定句,否定句中一般用many或much,如：
There’s a lot of work to do and a lot of people have been sent there.
有许多事情要做,许多人已派去那里了.
五、用于固定搭配构成习语.
have a lot to answer for为糟糕的情况负责
Jerry’s got a lot to answer for.If it weren’t for him,Ann would never have left Denver.
杰里要为这一后果负责.如果不是为了他,安永远也不会离开丹佛（美国科罗拉多州）.
have a lot on your plate有很多困难的工作要处理
Leave Mum alone-she’s got a lot on her plate at the moment.
不要管妈妈―——她眼下有太多的事要处理.
I can’t take a holiday at the moment; I’ve got a lot/far too much on my plate.
我现在不能休假,我有太多的事要处理.
have a lot on/have a lot going on 近期很忙
Do you have a lot on for tonight?你今晚很忙吗?
They will have a lot on tomorrow.他们明天将很忙.
have a lot on one’s mind把很多事情挂在心上
He is a businessman.He always has a lot on his mind.
他是一个商人.他总是记挂着很多事情.
see + n.(a lot/little/less/more/much/nothing/something) + of + sb./sth.……见到某人/物
We hope to see lot of you during the holidays.我们希望在假期里经常能看到你.